The invention concerns an autonomous radio timepiece having a flexible magnetic antenna.
The expression "radio timepiece" used herein is intended to signify a receiver for coded, absolute time information periodically transmitted by radio, when then decodes and displays the information received; it is not intended to signify a radio or television receiving device (carried for example on the arm) or a personal paging device that may be equipped additionally with a timepiece.
In the case of an autonomous radio timepiece, the receiver is equipped with a timekeeping circuit in order to advance the time display during intervals in which no valid time information is being received (e.g., during intervals of transmission interruptions or international deactivations for conserving energy). A valid time information is one that satisfies certain plausibility conditions, which for example are present if two time informations received in succession exhibit exactly the time difference known and given by the transmitter. If the instantaneous time display does not coincide with the instantaneously determined valid time information (due for example to display errors or a daylight saving change in time), the display is corrected by means of the instantaneously received valid time information, and the advance is resumed from this corrected position by means of the timing pulse generator of the internal timekeeping circuit. For details, reference is made to German Document GM 88 15 378 and U.S. Pat. No. 4,947,179 concerning a radio timepiece of this generic type, the disclosures of which are incorporated by reference herein.
It is an object of the invention to provide an efficient and readily manufactured autonomous radio timepiece of this generic type in the form of a wristwatch.